The present invention relates to an improved target for use in pinball machines, and in particular to a spinning target which is responsive to the force of impact of the pinball on the target.
Pinball games in which a solid metal ball moves randomly about a flat playfield have been in common use for years. Various targets are located on the playfield, and points are scored as the pinball impacts the targets. Manually operated devices such as plungers and flippers are used to keep the ball in play, and the object of the game is to obtain as high a score as possible by impacting as many targets as possible before the pinball leaves the playfield.
As a general rule, the targets used in such pinball machines register a score based solely upon a count of the number of impacts on the various targets, with the different targets having varying point values, and no attempt is made to gauge the force of impact on the target for scoring purposes. Examples of such targets are found in U.S. Pat. No. 3,430,959 to Ross et al., in which a flat target is rotated through an arc of nearly 180.degree. against stop, and U.S. Pat. No. 3,452,988 to Zale, in which a wire gate is flipped open. A wide variety of other such targets are known in the art.
U.S. Pat. No. 3,627,318 to Garbary et al illustrates a device in which a lever target is used to determine score based upon the force of impact of the pinball on the target. However, as is evident from a cursory review of this patent, devices of the Garbary type are complex relative to standard pinball technology, and are not commonly used.
Attempts have been made in the past to use a spinning target in which the number of revolutions of the target, based upon the force of impact of the pinball on the target, is used to determine the score. Unfortunately, such targets as used in the past have a relatively low moment of inertia about their axis of rotation because they are constructed of homogeneous molded plastic, even if they have a dumbell cross-section which increases the amount of inertia to some extent. This low moment of inertia renders the targets highly subject to frictional forces, and such targets cannot be relied upon to provide consistent scoring, particularly when the device becomes worn through use. Also, many such devices have eccentric weights, rendering them even further subject to the vagaries of frictional forces.